INVERSION OF MICROGRAVITY DATA AROUND SIAH BISHEH DAM, FOR DETERMINATION OF SUBSURFACE STRUCTURES IN A TUNNEL CONSTRUCTION PATH

Q: How can I download an article?

To download an article from SID, first log in to the site, search for the article title, and click on the 'Download Article' option.

Q: How can I download an ISI article?

To download an ISI article on SID, enter the keyword or article title in the search bar, view the relevant results, click on the desired article, and select the 'Download Article' option.

Q: How can I access the SID database?

To access the SID database, visit SID.ir, create an account, and log in to access scientific resources.

Q: Is downloading articles from SID free?

Some articles on SID are available for free, while others require payment. Details are specified on the article's page.

CHEGENI M.; MIRZAEI M.; BABAEI M.; ARDESTANI E.V.

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

Journal Paper

Paper Information

Journal: Journal of the Earth and Space Physics Year:2017 | Volume:43 | Issue:2 Page(s): 261-280

Download Full-Text

Persian Verion

View:

529

Download:

Cites:

Information Journal Paper

Title

INVERSION OF MICROGRAVITY DATA AROUND SIAH BISHEH DAM, FOR DETERMINATION OF SUBSURFACE STRUCTURES IN A TUNNEL CONSTRUCTION PATH

Author(s)

CHEGENI M. | MIRZAEI M. | BABAEI M. | ARDESTANI E.V. | Issue Writer Certificate

Keywords

MICROGRAVITYQ2

GRAVITY ANOMALYQ1

3-D INVERSIONQ1

CONTRAST DENSITYQ1

TUNNELQ1

COMPACTNESSQ2

Abstract

The gravity method is one of the geophysical tools used for geological, engineering and environmental investigations where the detection of geological boundaries, cavities, subsurface karstic features, subsoil irregularities, or landfills are essential. In higher accuracy measurements, the MICROGRAVITY method has been widely and successfully used for locating and monitoring subsurface materials.Since MICROGRAVITY methods measure gravity variations at the surface, they are directly influenced by the density distribution in the subsurface and particularly by the presence of formation material, which may create a mass deficit relative to the density of the surrounding terrain. In many cases, deep or small-scale heterogeneities generating low-amplitude anomalies can be detected and the reliability of further interpretation requires highly accurate measurements which are carefully corrected for any quantifiable disturbing effects. The main purpose of the research, that was conducted in small part of a dam site, is to determine the quality and type of subsurface structures in location of TUNNEL construction. Study area for collecting MICROGRAVITY data was located at a small part, considered for construction of Siah Bisheh dam, road Tehran to Chalous. Position of MICROGRAVITY stations were over a TUNNEL path which in some parts encountered with collapsing structures. The study area was part of Alborz Mountains. Geology formation (Shemshak formation), consisting of lime beds together with igneous rocks which are severely affected by fractures. Data were collected along 13 profiles with separating distance of 15 m. The stations distance and number of data were 15 m and 148 respectively. Bouguer GRAVITY ANOMALY was calculated after making corrections such as earth tide, free air, Bouguer, topography and terrain effects. The regional effect obtained using a program that is written in FORTRAN to fit orthogonal and orthonormal polynomials on the observed data and then residuals were estimated. Three negative anomalies were distinguishable in residual gravity map. Data of these anomalies are modeled with a 3-D INVERSION approach using GROWTH 2.0 software. The GROWTH 2.0 is an inversion tool which enables the user to obtain, in a nearly automatic and non-subjective mode, a 3D model of the subsurface density anomalies based on the observed GRAVITY ANOMALY data. The current version of the tool has been developed from an earlier code (Camacho et al., 2002). In a nearly automatic approach, the software provides a 3-D model informing on the location and shape of the main structural building blocks of the subsurface structures. Then densities contrast of these anomalies was estimated. Result of the inversion was a 3-D distribution of densities contrast.To show this distribution of the densities contrast, the horizontal and vertical sections at different depth and different horizontal positions were selected and interpreted. From these sections it is indicated that the effective depth of the data, for identifying martial of subsurface structures from the inversion, is about 50 m. In the sections, areas with low densitig contrasts are related to the fractured limestone and those with high contrast ones are related to the compact limestone or igneous rocks. Existence of igneous and lime rocks that have more density and COMPACTNESS, increase the quality of the structures in the path of the TUNNEL construction. Areas including fractured limestone, with lower density, decrease the quality of the structure and increase the risk of water permeability and collapsing in the path of the TUNNEL construction. Thus by interpreting of the results of the MICROGRAVITY data inversion, areas with high and low COMPACTNESS and good and bad quality rocks for TUNNEL construction are recognized, those are related to the fractured or karstic limestone and limestone and igneous rocks. Also boundaries of these formations where densitig contrasts vary suddenly, are related to the existence of faults.

Cites

No record.

References

No record.

Cite

APA: Copy

CHEGENI, M., MIRZAEI, M., BABAEI, M., & ARDESTANI, E.V.. (2017). INVERSION OF MICROGRAVITY DATA AROUND SIAH BISHEH DAM, FOR DETERMINATION OF SUBSURFACE STRUCTURES IN A TUNNEL CONSTRUCTION PATH. JOURNAL OF THE EARTH AND SPACE PHYSICS, 43(2 ), 261-280. SID. https://sid.ir/paper/80316/en

Vancouver: Copy

CHEGENI M., MIRZAEI M., BABAEI M., ARDESTANI E.V.. INVERSION OF MICROGRAVITY DATA AROUND SIAH BISHEH DAM, FOR DETERMINATION OF SUBSURFACE STRUCTURES IN A TUNNEL CONSTRUCTION PATH. JOURNAL OF THE EARTH AND SPACE PHYSICS[Internet]. 2017;43(2 ):261-280. Available from: https://sid.ir/paper/80316/en

IEEE: Copy

M. CHEGENI, M. MIRZAEI, M. BABAEI, and E.V. ARDESTANI, “INVERSION OF MICROGRAVITY DATA AROUND SIAH BISHEH DAM, FOR DETERMINATION OF SUBSURFACE STRUCTURES IN A TUNNEL CONSTRUCTION PATH,” JOURNAL OF THE EARTH AND SPACE PHYSICS, vol. 43, no. 2 , pp. 261–280, 2017, [Online]. Available: https://sid.ir/paper/80316/en

Related Journal Papers